Potential Complications of Carrying Twins

Expecting more than one baby can come with some extra risks, but they're not as many as you'd think.

Finding out you're carrying twins can come with double the joy and excitement. It may also mean you have more questions about your health and the health of your little ones. It's true that extra babies come with some extra risks, but not as many as you'd think. Not all twin pregnancies are classified as "high risk." Most moms expecting multiples have relatively uneventful pregnancies — at least in terms of complications. Also, while some risks and complications are harder to avoid, you may be able to prevent many of them. Here's what you need to know in case you encounter any along the way.

Potential Complications for Babies During Twin Pregnancy

Early labor and low birthweight. Twins, on average, come out sooner — and smaller — than singletons. Your womb may be a cozy place, but it can get crowded in a hurry as they grow. That's why full term for twins is considered 38 weeks, not the typical 40 weeks. Premature birth — delivery before 37 weeks of pregnancy — is the most common complication when you're pregnant with multiples. About 59 percent of twins are born early. Twin delivery, on average, occurs around 35 to 36 weeks. Triplets and quadruplets may come even sooner. Moms of singletons, on average, deliver at 39 weeks.

Since many twin births happen early, the average twin arrives weighing just 5 1/2 pounds. This is considered low birthweight, but most 5-pounders end up doing just fine, thanks to medical advances in caring for small newborns. Twins born at 3 pounds or less are at increased risk for health complications during infancy and long-term complications such as cerebral palsy and learning disabilities.

To reduce your babies' risk: Know the signs of premature labor. Call your doctor if you experience any of them.

Signs of early delivery can include:

Persistent cramping (like period cramps that can but don't always include diarrhea, nausea or indigestion)

Most moms who experience these symptoms don't give birth early, but it's worth checking in with your practitioner nonetheless.

You'll also want to make sure you're taking care of your health, and maintaining a good pregnancy diet that includes the extra calories (about 600 per day for twins) you may need to help maintain your babies' growth in utero.

Twin-to-twin transfusion syndrome. This is an in-utero condition where twins get an uneven amount of blood. One fetus can get too much blood while the other gets too little. It's a rare complication that happens in about 9 to 15 percent of pregnancies where identical twins share the same placenta. Though this condition is not dangerous for mom, it can be dangerous for babies.

To reduce your babies' risk: Your practitioner might refer you to a perinatologist. A perinatologist is a doctor who specializes in pregnancy complications. The perinatologist may perform laser therapy on the placenta to stop the flow of blood from one twin to the other. Your doctor may also opt to drain excess amniotic fluid with amniocentesis every week or two to reduce the risk of preterm labor with this complication.

Potential Complications for Expecting Moms During Twin Pregnancy

Preeclampsia.Preeclampsia is a pregnancy complication where expectant moms develop high blood pressure. Any pregnant woman can develop preeclampsia, but it's more common among moms expecting multiples. More placenta — and the added hormones that come with two babies — can lead to high blood pressure and preeclampsia. The condition affects one in four moms of twins. If it's not treated, preeclampsia can be dangerous for mom — triggering seizures and premature delivery. But thanks to careful monitoring, it's usually caught early.

To reduce your risk: There's no way to prevent preeclampsia, but it's important to start prenatal care early and continue it through pregnancy. Your practitioner will monitor your blood pressure carefully, so that if you do get preeclampsia you can treat it right away.

Call your doctor right away if you experience any of the following symptoms as they may be signs of preeclampsia:

Swelling of the hands and face or area around your eyes

Sudden weight gain over one to two days

Vision issues or headaches

Rapid heartbeat

Gestational diabetes. Moms expecting multiples are more likely to have high blood sugar levels during pregnancy. Doctors don't know for sure what causes gestational diabetes. They think that pregnancy hormones may block the ability of some mothers' bodies to use insulin, the hormone that helps your cells turn food into energy by absorbing sugars from the bloodstream. Gestational diabetes can increase your baby's birthweight and raise the risk of delivery complications if it's not detected. Luckily, diet can usually control or even prevent gestational diabetes, though some women may need extra insulin.

Placental problems. Women carrying multiples are at a higher risk of placenta previa (low-lying placenta) and placental abruption (premature separation of the placenta). Careful monitoring can prevent placenta previa from posing any significant risk. While placental abruption can't be detected before it happens, there are steps your doctor can take to avoid further complications should it occur.

To reduce your risk: Regular prenatal checkups during pregnancy will help ensure your practitioner can detect any placental problems and take steps to avoid further complications.

Complications of Carrying Twins Conceived Via IVF

Since IVF can be costly, many women undergoing the procedure often transfer two or more embryos to hedge their bets that one will survive to full term. But occasionally all the transferred embryos survive, which can result in multiples. If you are carrying twins conceived via IVF, the possible risks and complications, with one exception, are generally the same as they would be for women who conceived twins naturally.

Postpartum depression. Some research studies have suggested that women who conceive using assisted reproductive technologies such as IVF are at a greater risk of developing postpartum depression than women who conceive naturally. Other studies show that moms of multiples are more likely to get postpartum depression. Since women who conceive with IVF often have multiple births, it's not clear which factor might be responsible for the association.

To reduce your risk: Speak up if you're feeling any symptoms of postpartum depression, such as intense sadness or anxiety after giving birth. While some of that is normal, excessive emotion that interferes with your daily functioning warrants a call to your practitioner, who can help you get the help you need before it interferes with recovery and the early days of parenting.

Potential Complications During Delivery of Twins

When you have two babies to deliver, birth can get a little more complicated. Not surprisingly, twin births have more variables — and surprises — than single births. But since you'll be getting two for one labor, you'll get a pretty good deal no matter how it all plays out. Here are some potential complications that can happen.

Unplanned cesarean delivery. Many moms who are expecting twins have successful vaginal births. If you are preparing for a natural delivery with twins, it's important to understand that there's a greater likelihood your pregnancy may require an unplanned c-section. Delivery procedure will depend on the positioning, health and weight of each baby and how labor is progressing. Certain conditions, such as preeclampsia, may also up your chances of an early, unplanned c-section.

Mixed delivery. In very rare cases, it might be necessary to deliver your second baby by c-section after the first baby has been delivered vaginally. This is usually only done in an emergency situation such as a placental abruption or a cord prolapse (where the umbilical cord drops into the vagina ahead of the baby). A mixed delivery can be scary, and it means postpartum recovery from both vaginal and surgical delivery. But when it's necessary, it can save the life of your little one, which is well worth the added recovery time.

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From the What to Expect editorial team and Heidi Murkoff, author of What to Expect When You're Expecting. Health information on this site is based on peer-reviewed medical journals and highly respected health organizations and institutions including ACOG (American College of Obstetricians and Gynecologists), CDC (Centers for Disease Control and Prevention) and AAP (American Academy of Pediatrics), as well as the What to Expect books by Heidi Murkoff.